DE2253446A1 - AEROSOL CAN - Google Patents

Abstract

A pressure release valve is located in the domed bottom of an aerosol can. A centrally located area in the domed bottom having a lesser resistance to eversion than the peripheral area in the domed bottom includes several score lines which meet at a common point in a spoke-like configuration. The centrally located area of the bottom will evert at a pressure of 170 to 200 p.s.i. so as to rupture the bottom at the source lines before any substantial eversion of the peripheral area occurs.

Description

PATENT LAWYERS

HELMUT SCHROETER KLAUS LEHMANN DIPL.-PHYS. DiPL.-ING. 8 MUNICH 25 · LI POWSKYSTR. JO -

Crown Cork & Seal Company, Ine »cc-35

L / Bi. 51. Io. 1972

Aerosol can

Aerosol cans that have a propellant inside, such as Preon have, "represent a constant danger to the environment. If such a can is unusually high temperatures is subjected, dangerously high pressures build up inside the can. Under these circumstances, the bottom of the can can become damaged outwards, the can may explode and parts of the can may enter the can at dangerously high speeds Environment. Such circumstances can occur not only during the calcining or ashing of the cans, but even during storage at high temperatures. To ensure safe drainage of the built-up inside the can To enable pressure, a safety valve must be provided.

It has been proposed to form such a pressure relief valve, notch the aerosol can in various areas. US patent j5,074,6o2 discloses a pressure relief valve which is formed by notching the upper part of the can carrying the valve cap of the spray device. Notching will probably made there at the point where the largest

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PojudieckkontoMunchen 1679 41 · Deut »** Bulk Munich account 70/37369 · Telegrams: Sdiioepie Munich ■ Telephone: (08 11) 77 89 56

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Deformation occurs when the can is subjected to abnormally high internal pressures. This weakening of the valve cap of the can is intended to break open when there is a corresponding internal overpressure, so that the overpressure built up inside can be safely released. In two different exemplary embodiments of U.S. Patent 3 ° 7 ^ 6o2 are a circular score line and revealed a notch point.

U.S. Patent 3,292,826 discloses a pressure relief valve which is formed in that a relatively large section of the wall of an aerosol can at least partially with a line of weakness, e.g. a score line. As is apparent from the description of this US patent, the line of weakness lie on different parts of the wall of the can, but it should not be on the bottom of the can, as the pressure is released against a surface on which conventional cans normally stand, in the pressure relief valve disclosed in US Pat. No. 3,292,826 the result would be that the can would be displaced or lifted off this surface, which leads to complaints would lead.

The pressure relief valves described in the above-mentioned patents have a number of disadvantages. Only one of these drawbacks is that these valves do not allow the pressure built up inside the can to be relieved within a narrow pressure range of 11.95 to 14.06 kg / cm (170 to 200 psi). Although the first-mentioned US Patent 3 ° 74 6O2 an effective range between 12,3o and I4, o6 kg / cm (175 to 2oo psi for indicating the safety valve, the valve is not reproducibly effective in this area. The reason for this lies in the essentially in the small size of the notch area, the one

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requires a very low residual wall thickness, and this low Wall thickness cannot be maintained uniformly and leads to an unreliable triggering of the print.

The score line according to U.S. Patent J5,292,826, which is shown in FIG cylindrical wall of the can body is arranged, also requires a very small residual wall thickness, e.g. of 0.025 mm (ο, οοΐ inches) with a circle diameter of the score line of about 25.4 mm (1 inch). This small residual wall thickness is required since there is very little or no deformation of the cylindrical wall outside the score line, However, such a small residual wall thickness can be mass-produced due to inclusions and differences in the Difficult to achieve sheet thickness. The result is an unreliable one Triggering and an unreliable release of pressure from the can. As when reaching a pressure of about 14, o6 kg / cm (2oo psi) the bottom of most aerosol cans protrudes outwards, with the result that the double bead is formed or the double fold on the perimeter of the floor loosens, it is necessary for the pressure to be released before .this dangerously high pressure level is reached.

It is of course just as important to prevent premature release of pressure, e.g. releasing below one Pressure levels of 11.95 kg / cm (17o psi) »This is extraordinary important because a pressure of about 11.25 kg / cnr (l6o psi) can be reached during normal operation of the can without a real risk of explosion at this pressure

level exists. Therefore, depressurization at 11.25 kg / cm (16o psi) result in unnecessary destruction of an aerosol can and its contents rendered useless «

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Another disadvantage of the known pressure relief valves concerns the aesthetic appearance of the aerosol cans. Easily visible Score lines on the outside of the can are not pleasing to the eye. This is especially true when the score line is is located on the outside of the can wall and extends over a large area, such as in that U.S. Patent 3,292,826.

The manufacturing technique used in the formation of the pressure relief valve according to US Patent 3c-7 ^ 6o2 is used This patent discloses the use of an inert gas shielded electrical Tungsten arc to notch the valve cap of the aerosol can. This patent explicitly cautions that this technique can result in a notch that is too deep, creating a hole can arise in the valve cap. In addition, this method of scoring is relatively expensive and therefore not very special suitable for the can industry where high speed, low cost production is required.

The 'invention is therefore based on the object to create an aerosol can with a safety valve that is in a Pressure build-up inside the can reliably triggers at a certain pressure level before a dangerously high pressure level is achieved. The valve should not trigger prematurely. The aesthetic properties of the can are not intended are adversely affected and the valve should be inexpensive to manufacture. It should be a pressure relief valve or safety valve in the bottom of an aerosol can, which does not cause the can to be thrown away when the pressure is released or is released, even if the can is on its bottom.

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According to the invention this is achieved essentially in that the bottom has an outer, essentially concave region and has a central area that has a lower resistance to outward protrusion than the outer area, that the middle area is notched in a toll, which is essentially at the level of a centrally located point this area is, and that the design is such that the central area is at a predetermined pressure outwardly protrudes, while the outer region remains substantially concave, and that the notched part when protruding of the middle area breaks open.

The safety valve or pressure relief valve is therefore in the preferably arranged inwardly retracted or curved bottom of an aerosol can. The valve contains a for Protruding to the outside specific area that offers a lower resistance to the protruding than that of the everting area surrounding outer area of the can bottom. By making a score line within the protruding area, the remaining wall thickness leaves, which is much less than the normal wall thickness of the curved bottom, the valve solves reliably with a pressure build-up inside the can in a pressure range between 11.95 and 14.06 kg / cm (17o to 2oo psl), if the area of the can bottom that can be turned out protrudes outwards.

The bottom of the can can be scored to a residual wall thickness of 0.05 to 0.13 mm (0.02 to 0.005 inches), with multiple pairs of rectilinear score lines can be formed in a spoke-like arrangement on opposite sides Sides of a point arranged in the bottom of the can

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could be. The score lines, preferably on the outside of the bottom can also be produced and graded in a multi-stage Arbeltsverfahren be.

A first exemplary embodiment is that which is outwardly aurable The area of the donut floor is flat to offer less resistance to the protrusion. With a second The exemplary embodiment is the area that can be developed by means of a Surrounded by weakening line, in this way a lesser one To offer resistance to bulging.

In a third embodiment, the contains to the outside configurable areas a plurality of curved score lines, which are arranged between the straight score lines, but at a distance from them.

The invention also relates to a method of manufacture an aerosol can with a bottom that is in particular drawn in or curved inwards, or for the production of a Safety or pressure relief valve in the bottom of the can. In the Manufacture of the safety valve according to the first execution example is first a centrally arranged flat area a curved can bottom raw, pre-notched. The base of the prekerblinle is then fine to a depth notched so that the desired remaining wall thickness remains. The centrally arranged flat area of the can bottom can be leveled at the same time as the notch. at the manufacture of the safety valve after the second exit

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As an example, the line of weakness can be obtained by leveling and notching a curved bottom of the can and then re-arching the bottom, as a result of which an inwardly curved, bubble-like area is achieved .

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Execution examples of the invention are based on the following described in the drawing.

Flg. 1 is a side view of an aerosol can.

FJg. 2 is. a section through part of the indented inward Bottom of the aerosol can, which with the cylindrical side wall of the can of Figure 1 through Double beading or joint double hemming can be connected.

FIG. 3 is a plan view of the outside of the in FIG shown can bottom with the safety valve.

Fig. 4 is a section through the bottom of the can according to the figures 2 and 3 after triggering and releasing excess pressure through the valve.

Fig. 5 is a partial plan view of the exterior of the Can bottom of Figures 2 and 3 after releasing the excess pressure through the valve.

6 is a sectional view of a score line taken along line 6-6 in FIG.

Fig. 7 is a sectional view of another type of score line.

Flg. Figure 8 is a top plan view of the outside of a can bottom with the score lines altered.

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Figures 9a to 9e illustrate a method of manufacture of the safety valve according to the example according to FIGS. 1 to 6.

Fig. Io is a plan view of the grooving punch according to Line lo-lo in Figure 9b

11 is a top plan view of the finishing scoring punch of FIG the line 11-11 in Figure 9d.

Fig. 12 is a top plan view of the finished notch counter-punch taken along line 12-12 in Fig. 9d.

Figure 13 is a section through an inwardly drawn one Can bottom according to another exemplary embodiment, which follows with the cylindrical side wall of the can Figure 1 by double beading or twice together Folding can be connected.

14 is a plan view of the outside of the can bottom according to FIG. 13, showing the safety valve.

Figures 15a to 15e illustrate a method of manufacture of the safety valve according to the exemplary embodiment according to FIGS. 13 and 14.

16 is a plan view of another can bottom with another embodiment of the safety valve according to the invention.

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Flg. 17 is a partial sectional view of that shown in FIG shown can bottom according to line 17-17

Fig. 18 is a top plan view of the notching punch used for Production of the safety valve according to Figures 1.6 and 17 can be used.

19 is a sectional view of the notch punch according to FIG Line 19-I9 in FIG. 18 when engaging in the bottom of the can according to FIGS. 16 and 17.

Flg. Figure 2o is a sectional view of the notch punch of Figure 18 taken along line 2o-2o engaging the can bottom according to figure l6 and 17 ·

The aerosol can shown in Figure 1 has a side wall Io and a top 12 which houses a valve assembly including a valve cap 14, a valve stem 16 and a nozzle which can be pressed down on a surface 2o by a finger. An inwardly drawn-in bottom part is with the bottom edge of the side wall Io by double beading or connected by folding them twice together.

According to an exemplary embodiment of the invention, which is shown in the Figures 2 and 3 is shown, the aerosol can according to Figure 1 is provided with a safety valve that has a notched has flat area 24, which is arranged centrally in the inwardly drawn-in bottom 22 and by a outer concave peripheral region 26 surrounded 1st. Multiple score lines 2üa to 28h in the flat area 24 meet at one

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common point: · j5o together and thus form a spoke-like Template. The score lines of score line pairs 28a and 28e, 28b and 28f, 28c and 28g, as well as 28d and 28h, are diametrically opposed arranged opposite sides of the point 3 °.

It can be seen from FIGS. 4 and 5 that the flat area 24 can protrude outwards as a result of a pressure build-up inside the can, so that the bottom 22 breaks open at point 30 and thereby releases the pressure built up. However, the concave peripheral region 26 of the base 22 does not turn outwards. Tests have shown that the hole that forms at point 30 is so small that at a pressure of 11.25 kg / cm ² (160 psi) only about 65 dm ⁵ (2.3 cubic feet) of air escapes per minute. This is not enough to move the can in any way noticeably or significantly on a horizontal surface. The deformation at the can bottom _s, which is exaggerated in FIG. 4, is so small that the can bottom essentially returns to its undeformed position after the pressure has been released, whereby the hole at point 3o essentially closes again and the can contents run out is limited.

In accordance with the invention, the can bottom 22 will rupture at pressures no less than 11.95 kg / cm ² (170 psi) and no greater than 14.06 kg / cm (200 psi). In order to trigger the valve and release pressure within this pressure range, various conditions for the score lines 28a to 28h and for the flat area 24 must be carefully observed. For example, it has been found that an indentation to a residual thickness of 0.05 to 0.13 mm (0.02 to 0.005 inches) will trigger the valve in the pressure range between 11.95 and 14.06 kg / cm (170 to 2oo psi) results. In order to achieve a tripping - pressure from 11.95 to 13, oil kg / cm ² (l o to I85 psi?) Is a

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Notching st icfe in conjunction with a stepped, circular Depression 23 preferred, which is a residual thickness of o,] o mm (o, oo4 ZoIJ) in the area 27 tier spokes 20 and one Thickness of 0.076 mm (0.003 zoI) in area 29 of the spokes 28 results, which lies below the recess 25. Preferably the diameter of the recess 23 is about 7, H mm (9/32 zo] I).

In order to ensure compliance with this suitable residual thickness, a graduated score line, as shown in FIG. 6, is preferably used. The planar area 24 is first roughly pre-scored in order to form a score line 32 with a base area 34. The base area 3 ^ is then finely notched to the desired remaining thickness on the base area 36 of the finished score line 38 preferably o, o64 mm (o, oo25 inches) on the base 36 and an angle of 40 to 60 °, preferably ¹ o °, between the walls 40 of the two lines 38 delimiting the finished notch results in score lines that reliably produce the desired pressure height release.

Although the stepped score line shown in Figure 6 is preferred, For example, a conventional score line as shown in Figure 7 may be used if so appropriate Residual thickness can be achieved. Again, it has been found desirable to use an angle between 40 and 60, preferably 5o °, between the walls 42 and a width of 0.05 ms o, lo mm (o, oo2 to o, oo4 inches), preferably o, o64 mm (o, oo25 inches) to be provided on the base area 44.

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It is not just important to trigger the valve and one Ensure that the pressure is released before the pressure build-up reaches a level at which the double-crimped, or double ' folded bottom can peel off or pop out. It is also important to release the pressure prematurely to prevent the valve. Γη this connection was found that an arrangement of the score lines 28 on the outside of the base 22 ensures reliable triggering before a dangerous pressure level is reached, at the same time the maximum residual thickness of the floor is possible. An arrangement of the Score lines on the outside of the floor can trigger at a pressure of about 1.4 kg / cm (2o psi) lower than if the same score lines are arranged with the same residual thickness on the inside of the floor,

As FIGS. 4 and 5 show, a very small opening is created at point ^ o when the bottom 22 breaks open at the score lines 28. This is extremely important because the score lines are located on the bottom of the aerosol can and because the bottom is normally used to support the can on a horizontal surface. If the flow rate exiting through the opening or its flow rate is excessively high, the can can be overturned or perhaps even thrown off the horizontal surface. It has been found that the spout-like notch in a flat area of the bottom of the rosoldoso creates an opening through which only a limited flow rate can pass, which is insufficient to overturn the can on the horizontal surface, i.e. the fluid which has escaped between the horizontal surface and aw double flanging or double folding of the floor 22 in

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seep through in sufficient quantity and at sufficient speed can to tlLe you raw the opening in the bottom of the pants flowing Amount to compensate.

The design with six Grandpa Lohen for the Vent LL according to FIG. 8 is similar to the design mLt eight spokes according to FIG. 3. Preferably, the flat area has 2h ' for the design with six spokes and the flat area 2'l · for the design with eight Spokes have a diameter of about 19 »o5 mm ΟΛ inches) if an oil, 2 ^ kg-T-5 -steel (135 lb.T-5-Steel) is used to release at 12.65 kg / cm- ¹ "(18o psi). The radius of curvature of the bottom 22 is 58.9 j- 1.5 mm (2.319 f- o, o5o inches), and the total diameter of the curved bottom, measured on the inside of the double fold» , Is about 6h, lVj (2.353 inches) for both execution brackets, so that the flat herelch in both execution brackets has a diameter of less than a third of the diameter of the [iodine :;.

IIIn method for the manufacture averaging of the safety valve with the stepped KerblinLen 28 Ln the centrally disposed planar portion 2h will be described in connection with Figures 9a to 9e. FIG. 9a shows part of a curved base 22a before leveling and before notching. FIG. 9b shows a punch 52 in Vt; tbinding with an oegon punch 50, the punch 52 serving for the preliminary notching and at the same time for leveling the middle area of the dodens 22a. The bottom 22 ι is between the iJtübzf pool 5 ^ of the counter temple 5 'and the projecting K Hbf pool 56 de ;; upper temple 52 clamped and held, whereby the vorticerbtt; and in the middle

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leveled floor 22b is formed according to Figure 9c. In some In some cases it may be desirable to level the floor and notch the spokes in separate steps.

The pre-notched and leveled base 22 then takes a position between the finishing notching punch 6o and the counter punch 58 (Figure 9d). When the scoring surface 64 of the punch hits the bottom 22, which is on a stepped mating surface 62 of the counter punch 58 rests, the finely notched base 22c shown in FIG. 9e is obtained. ·

Figure Io shows an arrangement with eight spokes for the notch surface 56 of the punch 52. Flat sections 68 create the base j54 of the pre-notching lines, while inclined surfaces create the walls of the pith lines. FIG. 11 shows a fine notch surface 64 with eight spokes for the punch 60th level Sections 70 form the base 36 of the fine score lines, while inclined surfaces 72 form the walls 40 of those shown in FIG Form fine score lines. Finally, FIG. 12 shows a plan view of the stepped counter-punch 58 middle, stepped part 62 of the counter punch 58 carries for the generation of the remaining thickness of the score line in area 29 of the Soil concern, the area 29 being below the stepped area 62 so that it has a smaller residual thickness there than in the area 27 of the Kerbli'nien.

According to another, shown in FIGS AusfUhrungsbeispiel is the aerosol can of Figure 1 with a safety valve is provided which has an inwardly bulging or bubble-like area 124 which is centrally arranged in the inwardly retracted floor 22 and from

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an externally concave peripheral region 126 is surrounded. Several score lines 128a to 128h in the bubble-like area 124 meet at a common point I30 and thus form a memory-like pattern. The score lines of the score line pairs 128a and IiHIc ₁ 128b and 128f, 128c and 128g, as well as 128d and 128h are arranged on diametrically opposite sides of the point 13 °.

Around the area 124 against protruding outwards less To make more resistant than the surrounding area 126, the area 12 4 by a line of weakness in the form of a circular score line I32. If within the As pressure builds up, area 124 is ejected outward as a result of the pressure, as shown in dashed lines in FIG 13 shown int, so that the bottom 22 breaks open only at the point 13u and thereby releases the pressure. The surrounding Area 126 of the bottom 22 that is more resistant to eversion is than the area 124, but will not bulge outward.

At this embodiment example, the bottom cracks ? 2

2 a Drurli not below 11.9L kg / cm "(17o psi) and with a Dnirl '. Not / u-oßer air; 14.06 kg / cm" (2υο psi). Around the / ni :, ] ercji He ;; valve :, do] releasing de. '; Dnicks within (i1 (M, · l'rnrl;I'M ei eh :;; mi erhirbrn, iüü :: ;; en die verrciii eHenei, 1 hi7 (JIk 1 1 ι η in Her / _; u:; bi liiun /; de ;; valve :; ;; oi f 1 al ti \\ üher- WJK ¹ IiI VMiI (J). '/.!1... '! ^1] 1 «IIIe i ^<i: t d1 el c (i (r JiiHlnien IPfin 1 i.-i irmi!'\; f.ι .τη '' ( '' u.! i H ^';., J ^ ι; ri (ο, υοΓ: and ο, οο': I (ill) 1 11; ⁽ⁱ (, J: ν - :.> r ■■ ϊ <ι ι lun ii n, H; j V j-1 nc Ht ι \ H1 · k (\ ι> n ο, 1 <does 1 ( 'i'<4', (}}) ii; HiJiJi) Ti; ¹ / ^in.!:: [iiiii (·)! (hm i``rj'i> 3in »f η ΐ; ίίπ

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up to 128h and a remaining thickness of 0.076 mm (0.003 inch) in Area 129 of the spokes or score lines 128a to 128h, which is below a circular depression 125 with a Diameter of 7> l44 mm (9/32 inch) is preferred about triggering the valve and releasing pressure in the area

2
between 11.95 and I3 »oil kg / cm (17o to I85 psi) can be achieved (see also FIG. 15c). The weakening line 1] 52, which surrounds the area 124, is achieved by notching to a residual thickness of 0.254 (ο, οΐο inches). In this way, the score line I32 has a greater residual thickness than the score lines 128a to 128h, although this cannot be seen from FIGS. 15c or 15e.

Another critical aspect of the valve ^V shown in the figures I3 and 14 relates to the dimensions of the bubble-like portion 124. It has been found that an overall diameter of this range of 19 * C-5 mm (3/4 inch) and a bubble radius of curvature of 25> 4 mm (1 inch) are particularly effective. This gives a total bubble height of about 1.59 mm (1/16 inch). The above explanations relate to a floor made of 6l, 24kg T-r5 steel (135 Ib. Τ-5-steel) with a thickness of 0.38 mm (0.15 inches). The radius of curvature of the curvature of the bottom 22 is again 58.9 + 1.27 mm (2.319 + 0.05o inches), and the overall diameter of the curved bottom measured within the double rebate is about 64.85 mm (2.553 inches).

A method for manufacturing a safety valve with the inwardly bulging or bubble-like area, which is surrounded by a line of weakness and has score lines, which are arranged within the line of weakness is described below with reference to FIGS. 15a to 15e.

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FIG. 15a shows part of a curved base 122a before notching. FIG. 15b shows a stamp 152 for leveling and notching with a notch surface 153 in communication with a Counter punch 15o, which has a stepped support surface 151. This arrangement serves to notch the diode 122a and to form score lines 128a to 128h, 13o and 132, as shown in Figure 15c. After notching, the bottom 122a is made into a bending punch I56 and negen punch 154 existing tool introduced where the inwardly curved Area 124 is formed as shown in Figure 15e. In this way, the floor will initially be level notched and then bent inward to form the inwardly curved portion 124.

According to a further AusfUhrungsbeispiel the invention that As shown in Figures 16 and 17, a planar area 224 having a diameter of 7.5 mm (0.75 inches) is provided the outside of the domed can bottom 222 is notched so that five substantially straight score lines 226 are formed extending radially outward from a centrally located point 228. The flat area 224 becomes also notched so that a plurality of arcuate score lines 230 are formed, which are in a discontinuous circular ring-shaped Arrangement lie radially outside of the point 228 arranged in the center.

As can be seen from the drawing, each of these curved score lines 23o lies between a pair of adjacent straight score lines 226 at the radially outer end of those straight score lines. From the drawing it can also be seen that the

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Ends of each curved score line 23o a sizeable one Have a distance from the adjacent straight score line 226, in contrast to the exemplary embodiment according to FIG. 14, where the continuous circular score line 132 with the radially extending score lines 128a to 128h is connected at their ends.

The design of a notch punch for producing the valve shown in FIGS. 16 and 17 is shown in FIGS. 18 to 20. The fine notch surface, which can be used in place of the surface according to FIG. 9d, contains flat sections 232 for producing the base surface 238 of the score lines, while inclined surfaces 236 are used to form the walls 238 of the score lines. By using a stepped counter-punch with a central projection with a Durehmesser of about 1, 14 mm (9/32 inch) for supporting the bottom, the middle Dereich of the score lines with a residual thickness of 0.076 mm (0.003 inches) are provided, while the remaining thickness the remainder of the score line area is between 0.13 and 0.15 mm (0.005 and 0.006 inches). The notch creates a flat area 224 which, at pressures in the range from 11.95 to 14.06 kg / cm '"(17b to 2oo psi), jumps out or turns outward Part of the inner diameter of 7 * 14 mm (9/32 inch) broken open. - ·, .. /

Instead of napli inn on (ingerofdi, the linden d < The can is completely more pure. . -

Claims (22)

-2o cc-35 2253U6 PATENT CLAIMS Θ Aerosol can with a side wall, a top with a spray arrangement and a preferably inwardly drawn-in or curved base, characterized in that the base (22, 222) has an outer, has a substantially concave region (26, 126) and a central region (24, 124, 224), which has a smaller Resistance to protrusion outwards than the outer area that the middle area in one Part notched (28, 128, 226), which is essentially in the vicinity of a centrally located point (j5o »13 °, 228) this range is, and that it is designed so that the central range is at a predetermined Pressure protrudes outwards, while the outer area remains essentially concave, and that the notched Part breaks open when the middle area is turned out. 2. Aerosol can according to claim 1, characterized in that the bottom (22, 222) in the middle Area (24, 124, 224) has a pressure relief valve, which by at least one score line (28, 128, 226) 4n this middle area is formed so that the middle area 309821/0262 -21- ee-35 at an internal pressure above 11.95 kg / cm (I / o psi), but below 14.76 kg / cm (2Io psi), preferably below I4, o6 kg / cm (2oo psi) protrudes outwards, with the The bottom breaks open at the score line in order to release the contents of the can through an opening formed by the breaking open, without the outer concave area of the bottom bulging outwards significantly. 3 · Aerosol can according to claim 1 or '2, characterized in that the central area (24, 224) in the is essential. 4. Aerosol can according to claim 1 or 2, characterized in that the central region (124) is like a bubble is arched inward and surrounded by a line of weakness (132). 5 aerosol can according to at least one of the preceding claims, characterized in that the score line (28, 128, 226) is straight. 6. aerosol can according to at least one of the preceding claims, characterized in that a plurality of score lines (28, 128) arranged in pairs is provided, each with the lines of a pair diametrically opposite one another on opposite sides of a point, especially the center point (3ο, 13o) of the central region (24, 124) are arranged. 309821/0262 -22- cc-35 7. aerosol can according to at least one of the preceding claims, characterized in that the Score lines (28, 128, 226) are located entirely within the central area (24, 124, 224). 8. Aerosol can according to claim 7 , characterized in that the score lines (28 ') consist of six score lines arranged at equal angular intervals. 9. Aerosol can according to claim 7 *, characterized in that the score lines (28, 128) consist of eight consist of score lines arranged at equal angular intervals. 10. Aerosol can according to at least one of the preceding claims, characterized in that the score lines (28) are stepped and a pre-notch (32) and have a finished notch (38) within the front notch, and that the bottom (22) on the base (36) of the finished notch has a residual thickness of 0.05 to 0.13 mm (0.02 to 0.005 inches). 11. Aerosol can according to claim lo, characterized in that g e k e η η - ζ e i c h η e t that every notch (28, 128, 226) in the Near the central point (30, 13o, 228) of the middle one Area (24, 124, 224) has a smaller residual thickness than at the edge of the central area (depression 25, 125 Floor 22). 309821/0262 -23-. cc-35 2253U6 12. aerosol can according to at least one of the preceding claims, characterized in that the largest diameter _s of the central region (24, 124 * 224) is less than one third of the diameter of the bottom (22, 222). 15 · Aerosol can according to claim 6, characterized in that the score lines (28, 128, 226) in the are essentially straight "and extend from a centrally located point (3o, 13ο, 228) of the central area (24, 124, 224) extending radially outward » 14. Aerosol can according to claim 13 »characterized in that radially outside of the centrally located Point (228) a series of curved score lines (230) in a broken circular order is arranged and that each of these curved notch = · lines between two adjacent straight lines Score lines (226) is arranged » 15. Aerosol can according to claim 14, characterized in that g e k e η η that the ends of the curved score lines (230) are a considerable distance from each of the two adjacent rectilinear score lines (226). 16. Aerosol can according to claim 15p, characterized in that the curved score lines (230) in the substantially equidistant from the central point (228) are the outer ends of the straight score lines (226). 309821/0282 -24- cc-35 17. Aerosol can according to one of claims 14 to 16, characterized characterized in that five straight score lines (226) and five curved score lines (23o) are present are. 18. Aerosol can according to claim 4, characterized in that the weakening line (1J52) through a substantially circular notch is formed. 19 · A method for producing an aerosol can with a bottom that is particularly drawn in or curved inwards, characterized in that the bottom (22, 222) is notched in a flat central area (24, 124, 224). 20. The method according to claim 19, characterized in that the bottom (22) additionally to the central flat area (124) is notched around (I32) and that then the bottom (22) for formation an outer concave area (126) and an inwardly arched central area (124) arched inwardly will. 21. The method according to claim 19 * characterized in that first the bottom (22) in the middle flat area (24) is notched (32) and that then the base (34) of the front notch (32) to form a finished notch (38) with a residual wall thickness of 0.05 to 0.13 mm (0.05 to 0.13 mm (0.02 to 0.05 inches)) of the bottom. 309821/0262 -25- cc-35 22S344S 22. The method according to claim 21, characterized, in that the vaulted first inside bottom (22) _s is deformed such that a central planar region (24) is formed, and that simultaneously the central planar portion is notched to form the Vorkerbe. 3 09821/0262